EP0423102A1

EP0423102A1 - Apparatus and method for controlling the operation of a fluid flow control valve in response to the presence of a human body part

Info

Publication number: EP0423102A1
Application number: EP90870178A
Authority: EP
Inventors: Karel Van Marcke
Original assignee: International Sanitary Ware Manufacturing Cy NV SA
Current assignee: International Sanitary Ware Manufacturing Cy NV SA
Priority date: 1989-10-10
Filing date: 1990-10-10
Publication date: 1991-04-17
Anticipated expiration: 2010-10-10
Also published as: DE69007583T2; US5943712A; US6178572B1; US5086526A; EP0423102B1; HK1006736A1; DE69007583D1

Abstract

The invention relates to a method and an apparatus for controlling the operation of a fluid flow control valve (76) in response to the presence of a living body part comprising means for operating the valve in order to control said fluid flow therethrough, said operating means comprising means for opening and means for closing said valve, characterized in that it further comprises in combination :

(a) a sensor (22) for detecting heat radiating from a living body part within a predetermined detection field (20) and for producing an output signal in response to such detection ;
(b) a low voltage power source for energizing said apparatus ;
(c) means for determining the voltage of said power source ;
(d) means responsive to the output signal for comparing the determined voltage with at least one predetermined voltage and for generating a first control signal if the determined voltage is below the predetermined voltage ; and
(e) means for blocking fluid flow through said valve (76) in response to said first control signal.

Description

The present invention relates to an apparatus for controlling the operation of a fluid flow control valve in response to the presence of a living body part, comprising means for operating the valve in order to control said fluid flow therethrough, said operating means comprising means for opening and means for closing said valve.
Single or multi user wash basins used in industrial, commercial or public environments provide a source of water on demand for cleansing a user's hands, face and other body parts. Water flow valve actuating mechanisms are often manually or foot operated lever type devices to permit relative ease of use. The manually operated lever type devices may become soiled or otherwise damaged due to dirt and other contamination present on a user's hand prior to washing. The foot operated lever type devices are often subjected to abuse.
Dispensation of soap, whether liquid or powder, is usually achieved by manually operating a lever, a push button or a squeeze bottle; adaptations for operating such devices by foot are also known. To dry oneself, a user must manually grasp and pull individual folded paper towels from a dispenser, pull and tear off paper towels from a roll, pull down an endless cloth towel from an enclosed feed roller or push a button to actuate a hot air blower. All of these manually (and foot) operated devices accumulate a residue of dirt, bacteria and viruses at the locations of contact by the users. The constituents of this residue may contribute to the spread of disease and otherwise present a public health hazard.
To avoid the requirements for having a user physically actuate a valve in order to cause water flow at a wash basin, various sensors have been developed and incorporated with valve actuating mechanisms to sense the presence of a user at a wash basin. Actuating apparatus of this type have included devices for generating ultrasonic energy focused upon a detector; or, upon a change in the energy detected due to the presence of a user, a signal may be generated for actuating a water flow valve. in one water faucet device, the faucet is rotatable to permit automatic water flow actuation or require manual valve control as a function of the rotational position of the faucet. Various devices have been developed which include a light emitter with a corresponding detector. Upon interruption of the light path by a wash basin user, actuation of a water flow valve will occur. Audio responsive detectors for actuating water flow valves associated with water basins and the like are known. Infrared detector systems include a generator for generating a source of infrared energy and a detector responsive thereto. Upon interruption of the infrared energy by a user, circuitry is energized for actuating a water flow valve.
A common characteristic of prior art related devices for sensing the presence of a user and actuating a water flow valve and other devices is that such systems are active systems. That is, a signal generator is provided with a corresponding receiver. A change in signal intensity sensed by the receiver related circuitry and in response to the presence of a user, is detected and serves as a triggering signal for actuating a valve. The requirement for transmission of a signal, in combination with signal detection circuitry, imposes a requirement for a relatively substantial power supply.
A drawback of the known devices is that they need a relatively high power supply, which could render them unsafe, especially when used in washing facilities for human beings or drinking facilities for animals.
An object of the present invention is to provide an apparatus of the above defined kind which is safer and also reliable in use.
To this end an apparatus according to the present invention comprises further :

(a) a sensor for detecting heat radiating from a living body part within a predetermined detection field and for producing an output signal in response to such detection;
(b) a low voltage power source for energizing said apparatus;
(c) means for determining the voltage of said power source;
(d) means responsive to the output signal for comparing the determined voltage with at least one predetermined voltage and for generating a first control signal if the determined voltage is below the predetermined voltage; and
(e) means for blocking fluid flow through said valve in response to said first control signal.

The sensor of this apparatus according to the invention is a passive sensor which does not emit continuously a detection signal and which thus requires very little electric power allowing to use a low voltage power source. The blocking means provided in this apparatus avoid the possibility of the valve remaining open due to insufficient electrical power to effect closure of the valve and thus assures a save and reliable working of the apparatus.
In a first preferred embodiment of the apparatus according to the invention, said opening means are provided for opening the valve in response to the output signal, said blocking means being provided for closing the valve in response to said first control signal.
In this first embodiment, the blocking means are formed by a fail safe circuit for closing and disabling the valve in the closed position when the voltage of the power supply drops below a predetermined value.
In a second preferred embodiment of the apparatus according to the invention, said comparing and generating means are further provided for generating a second control signal if the determined voltage is above the predetermined voltage, and said apparatus further comprises means for enabling said opening means in response to said second control signal.
In this second embodiment, the possibility of the valve remaining open due to insufficient electrical power to effect closure of the valve is avoided by checking first if the voltage of the power source is above the predetermined voltage before opening the valve. The latter voltage is predetermined in such a manner that after opening of the valve the power of the power source is always sufficient to effect closure of the valve.
The present invention further relates to a method for controlling the operation of a fluid flow control valve in response to the presence of a living body part, comiprising opening and closing the valve, characterised in that it comprises the steps of :

a) supplying a low voltage power for said controlling of said valve;
b) detecting heat radiating from a living body part placed within a predetermined detection field and producing an output signal in response to said detecting;
c) determining said supplied low voltage;
d) comparing said determined voltage with at least one predetermined voltage in response to the output signal and generating a first control signal if the determined voltage is below the predetermined voltage; and
e) blocking fluid flow through said valve in response to said first control signal.

Other particularities and advantages of the present invention will become apparent from the following description of some specific embodiments of the invention. However, these specific embodiments are only given by way of illustrative example and should not be construed to limit the scope of the invention. The reference numerals relate to the annexed figures wherein :

Figure 1 illustrates a representative wash basin having superimposed therein the horizontal detection field attendant a wash basin mounted detector;
Figure 2 is a representation of the horizontal detection filed shown in figure 1;
Figure 3 is a partial cross sectional view of the wash basin and showing the vertical detection field therein attendant a wash basin mounted detector;
Figure 4 illustrates the vertically reduced detection field within the wash basin;
Figure 5 illustrates a representative vertical cross sectional view of a detection field attendant a water spout mounted detector;
Figure 6 illustrates representative components for implementing the detection apparatus;
Figure 7 is a block diagram of a discrete component detection circuit;
Figure 8 is a block diagram illustrating the electrical power source for the circuit depicted in figure 7;
Figure 9 illustrates representative discrete components of receiver and the amplifier circuits usuable with the detection system;
Figure 10 illustrates discrete components of a timer control for the detection system;
Figure 11 illustrates discrete components of a power output circuit for the detection system;
Figure 12 illustrates discrete components of a battery killer circuit for the detection system;
Figure 13 illustrates a flow diagram of the functions performed by an apparatus according to the invention; and
Figure 14 illustrates a configuration of three detection systems mounted on a three user positions washbasin.

In these figures, the same reference numerals indicate the same or analogeous elements.
Public wash basins of the type used predominantly in various industrial, commercial and public establishments require manipulation of levers, knobs, handles or push buttons to bring about water flow. Often, each of a hot and cold water tap must be adjusted to obtain a satisfactory temperature of the outflowing water. Such ongoing contact by dirty and/or contaminated hands promotes spread of bacteria and viruses due to the final manual contact to turn off the water flow after one's hands have been washed. The transfer of bacteria and viruses will contribute to the spread of disease. Where such diseases are life threatening or permanently disabling, the risks of using public wash basins become intolerable. Similar risks exist in actuating soap dispensers, supplies of towels, air driers and other ancillary apparatus.
Preferably, the act of washing one's hands or face in a wash basin available to the public should not require physical contact with any part of the wash basin, associated implements or ancillary equipment. Apparatus for automatically discharging water should discharge such water at a preset temperature and for a period of time sufficient only to complete a washing function in order to conserve water. The operative elements should be actuated as a function of the proximity of the user's hands or body. Means should be employed to eliminate or prevent false actuation and means should be employed to terminate water flow prior to a preset time if use of the water ceases. Moreover, ancillary equipment should be operated commensurate with the timing of the washing operation.
Any electrical power source and any electrically energized components must be of sufficiently low voltage and power level to eliminate any electrical hazard. As many washing facilities are remote from a ready source of electrical poker, the electrical power source for the actuating unit should be a low voltage battery. To permit uninterrupted operation, the power requirements of the operating system should have very low current consumption to permit use well in excess of a year and, preferably, for several years.
Referring to Figure 1, there is illustrated a top view of a representative wash basin 10. The wash basin includes a bowl 12, a drain 14 and a spout 16 for discharging water. To sense or detect the presence of the hands of a user, a detection field 20 is established primarily only within bowl 12. As illustrated in figure 2, the horizontal configuration of detection field 20 is generally round or ellipsoidal in cross section and conforming to a horizontal plane through bowl 12.
The vertical configuration of detection field 20 is best illustrated in figures 3 and 4. A sensor 22, responsive to a heat source such as a human body part within detection field 20, is usually located, for example, in rear wall 18 of bowl 12. The vertical parameter of detection field 20 is limited at the lower half of bowl 12. The upper limit of the detection field may be mechanically limited by a restrictor 24 used in conjunction with sensor 22. As particularly illustrated in figure 4, the original detection field for sensor 22 would include the volumes represented by areas 1, 2 and 3. Area 3 is eliminated by bowl 12, which bowl defines the lower perimeter of area 2. Upper area 1 may be eliminated by restrictor 24 operating in conjunction with the sensor. Accordingly, the detection field to which sensor 22 is responsive is essentially limited by the space within bowl 12 and extending in rounded manner slightly upwardly therefrom.
In certain applications it may be preferable to have the sensor, such as sensor 26, mounted upon water spout 16. Generally, detection field 20 will extend downwardly from sensor 26 into bowl 12 of wash basin 10. A restrictor 28 may be employed in conjunction with sensor 26 to define the downwardly extending cone angle or horizontal configuration and downward expansion rate of detection field 20.
Such limited detection field will prevent water flow during normal movement past wash basin 10 and essentially requires a user to place his hands or other body part essentially within the bowl of the water basin.
Referring to figure 6, there is illustrated a representation of the major components of the present invention which may be installed as original equipment or as retofit equipment in a wash basin. Module 30 includes a heat sensor or infrared sensor 22 (see figures 3 and 5) that may be penetrably mounted in rear wall 18 of a wash basin 20 (see Figure 3) or in spout 16 (see Figure 5). For reasons discussed above, the parameters of the field within which sensor 22 will detect a heat source represented by a body part is limited to the volume essentially within the wash basin. The sensor produces an output signal and a module 30 may include an amplifier for amplifying the output signal. To establish a threshold of operation for sensor 22, a regulating device 32 may be incorporated. The circuit attendant the regulating device may be contained within module 30 and be connected to the regulating device via conductor 34. The regulating device permits establishment of a threshold temperature for the sensor to accommodate variations in ambient temperature. A module 36, interconnected with module 30 through an electrical conductor or cable 38, includes timing circuitry for generating a control signal to provide power to actuate a water valve controlling the water flow through spout 16. Circuitry for deactuating the water valve, along with a time delay to minimize false actuations, are also contained within module 36. Because a certain amount of power is required to deactuate or close the water valve, it is mandatory that sufficient power be available to perform this function. Accordingly, blocking means form d by a fail safe circuit may be contained within module 36 to lock the water valve in the off or closed position when the source of power drops below a predetermined voltage (for example 7,5 volts if a standard 9 volt battery is used). A conductor 40 conveys electrical power to the water valve (not shown).
A characteristic of active detection systems is the transmission of a signal which is reflected from a triggering object to a receiver. Such transmission requires a substantial amount of power. A passive system is one in which a signal is received from the triggering element. For this reason, the power demand of a passive system is substantially less than that of an active system. Since the present invention is a passive system, and by careful circuit design, very little power is required for operation. To further reduce the power demand, low power consumption programmable microchip technology may be employed, as discussed in further detail below. Power consumption can be further reduced by having the system operate in a standby state until the presence of a human body part within the detector field triggers operation of the various control and timing functions. For this reason, a conventional nine volt battery 42 may be used as a power supply. The battery is electrically connected to module 36 via a conventional clip 44 and electrical conductors 46.
Referring to figure 7, there is illustrated a block diagram of a discrete component circuit and operation of detection system 50. Heat detector or sensor 22 is a dual element pyro electric heat detector specifically intended for battery operated passive detection systems. The sensor is for example of the type RPY97 or RPW100. It has diferentially connected dual elements which provide immunity from background radiation and noise. The spectral response of the sensor is in the range of five to fifteen µm; this is the range of the wave length of the infrared rays emitted by heat radiation from a human body part. The frequency range is 0.1 to 20 Hz; such low frequency range essentially eliminates any influence from ambient or expected acoustic noise sources. The quiescent power drain of the sensor is approximately 10 µA and represents a very low current drain. The dual elements are combined with a single impedance converting amplifier specially designed to require a low voltage power supply and the amplifier has a low current consumption. An output signal is provided by the sensor only upon occurrence of an imbalance of radiation impinging upon the dual elements. More particularly, the sensor contains ceramic plates sensitive to radiant heat and serving as electric dipoles permanently polarized which change polarity only upon a sudden change in voltage potential across the electrodes resulting from a sudden change of temperature. Since the sensor is not sensitive to ambient temperature, but only to a sudden change of temperature, the sensor is self adjusting and accommodates slow changes in ambient temperature. More specifically, one of the ceramic plates reacts to the ambient temperature while the other plate is subjected to heat irradiating from the human body. This change in temperature registered by the plates generates an output signal.
The output signal generated by sensor 22 is transmitted to a multistage circuit 52 including an amplifier to amplify the low level output signal generated by the sensor and a band pass filter. Means may be incorporated to permit adjustment of the threshold of the output signal received from sensor 22 and amplified by use of regulating device 32 (see figure 6) or the like. A leveled signal edge detector 56 detects positive and negative variations of a magnitude greater than a predetermined threshold of the signal received from multistage circuit 52 via conductor 58. The output of the signal edge detector is transmitted through conductor 60, hold off circuit 62 and conductor 64 to valve open timer 66 when the hold off circuit is not active.
The output of the valve open timer is transmitted via conductor 68 to pulse generator 70. On receipt of the output signal, the pulse generator will activate power driver 72 via conductor 74. The power driver will provide power to an electromagnetic valve, represented by numeral 76, to open the valve and permit water flow through spout 16. The output from valve open timer 66 is also transmitted via conductor 80 to a four second timer 82. After valve 76 has been open for approximately four seconds, timer 82 will transmit a signal via conductor 84 to a battery checker 86. The function of the battery checker is to determine whether the poker supply (battery) is maintaining a voltage above a predetermined level during energization of valve 76. Power driver 94 and closure of the valve require a predetermined amount of electrical power. Such power level can be translated to a minimum acceptable voltage at the power supply or battery if the characteristics of the power supply or battery are known. In the event the voltage sensed is below the predetermined value, an output is provided via conductor 88 to a battery killer circuit 90. The function of the battery killer circuit is to generate a first control signal for transmission via conductor 92 to power driver 94. On energization of power driver 94, an output signal is generated and transmitted via conductor 96 to close the water valve. This procedure will ensure that the water valve will not remain open due to a power drain or low voltage at the power supply.
Valve open timer 66 also determines the time during which the valve will remain open. On completion of this time period (nominally 20 seconds), a further output signal is generated and transmitted to pulse generator 100 via conductor 102. The pulse generator will provide a signal via conductor 104 to power driver 94 to close the valve. The second output signal is also transmitted to hold off timer 106 via conductor 108. The purpose of the hold off timer is to provide a delay of approximately six seconds before the valve can be opened again. Hold off timer 106 transmits a signal to hold off circuit 62 via conductor 110 to preempt or inhibit transmission of a signal via conductor 64 to valve open timer 66 prior to expiration of the delay period.
Figure 8 provides a representation in block diagram form of battery 42 energizing a power supply bus 112 from which a plurality of conductors extend to various components of detection system 50. The power supply is grounded, as represented by conductor 114.
Figure 9 through 12 illustrate the arrangement of discrete component circuitry represented by the block diagram illustrated in figures 7 and 8.

The following tables 1 through 4 give the identification or component values of components indicated in figures 9 through 12 by a reference numeral

Tabel 1

Value or identification of components from figure 9.
Ref. n°	Value or identification of Component	ref. n°	Value or identification of Component
500	1 k Ω	518	10 k Ω
501	470 mF	519	10 mF
502	56 k Ω	520	10 mF
503	10 mF	521	100 k Ω
504	10 M Ω	522	10 k Ω
505	0,1 mF	523	820 k Ω
506	47 mF	524	470 k Ω
507	100 k Ω	525	220 k Ω
508	5.6 M Ω	526	220 k Ω
509	12 M Ω	527	4.7 nF
510	TLC27L4CN	528	2.2 M Ω
511	1 k Ω	529	TLC27L4CN
512	1mF	530	3.9 M Ω
513	100 k Ω	531	10 M Ω
514	2.2 M Ω	532	2.7 M Ω
515	TLC27L4CN	533	2.7 M Ω
516	2.2 M Ω	534	TLC27L4CN
517	4.7 nF

Tabel 2

Value or identification of components from figure 10.
Ref. n°	Value or identification of Component	Ref. n°	Value or identification of Component
535	10 M Ω	549	22 k Ω
536	820 k Ω	550	100 k Ω
537	560 k Ω	551	2.2 M Ω
538	2.2 mF	552	100 k Ω
539	470 k Ω	553	15 nF
540	1 M Ω	554	TLC27L4CN
541	1.5 M Ω	555	100 k Ω
542	100 n F	556	22 k Ω
543	300 k Ω	557	470 k Ω
544	4.7 mF	558	TLC27L4CN
545	2.2 M Ω	559	15 nF
546	10 k Ω	560	2.2 M Ω
547	TLC27L4CN
	561	100 k Ω
548	220 pF	562	100 k Ω

Tabel 3

Value or identification of components from figure 11.
Ref. n°	Value or identification of Component
563	8.2 k Ω
564	39 k Ω
565	BC 327
566	BD 238
567	BC 327
568	8.2 k Ω
569	39 k Ω
570	BD 238
571	1000 mF

Table 4

Value or identification of components from figure 12.
Ref. N°	Value or identification of compounds	Ref. N°	Value or identification of compounds
572	560 k Ω	591	10 k Ω
573	BC 557	592	100 k Ω
574	10 M Ω	593	100 nF
575	560 k Ω	594	10 k Ω
576	150 k Ω	595	BC 549
577	33 mF	596	1.8 k Ω
578	1 k Ω	597	100 nF
579	22 mF	598	4,7 k Ω
580	33 k Ω	599	4,7 k Ω
581	47 mF	600	4,7 k Ω
582	5,6 M Ω	601	100 nF
583	82 pF	602	BC337
584	1 M Ω	603	1 k Ω
585	390 nF	604	1 k Ω
586	82 pF	605	3.9 V
587	TLC27L4CN	606	0,47 mF
588	5.6 M Ω	607	390 kΩ
589	68 k Ω	608	6.8 k Ω
590	1 M Ω	609	BC557
		610	6.8 k Ω
		611	270 k Ω
		612	100 k Ω

Since a circuit designer of ordinary skill in the art could build and use these circuits as a result of this information, a detailed description of the signal paths and functions of the various components need not be undertaken. Instead, certain features of these circuits will be highlighted in the discussion below. The output signal of sensor 22 appears on conductor 116. This output signal is detected and amplified by the operational amplifiers and a usable output signal is produced on conductor 118. Regulating device 32 (see also Figure 6) provides a trilevel sensitivity adjustment to accommodate for varying degrees of sensitivity desired. This is achieved by varying the feedback across operational amplifier 229.
Figure 10 illustrates the circuit for detecting the leading edge of the output signal on conductor 118, holdoff circuit 62, valve open timer 66 and pulse generators 70, 100. The output of the pulse generators is transmitted via conductors 74, 104 to power drivers 72, 94, respectively, illustrated in figure 11. Power applied via conductor 78 to valve 76 from driver 72 will open the valve. Similarly, power provided on conductor 96 to valve 76 will close the valve.
A signal appearing as output MMV1 in Figure 10 is transmitted to the circuit shown in figure 12. This circuit performs the function of checking the voltage of the power supply (battery). Upon determining that the voltage of the power supply is below a predetermined limit, an output signal will appear on conductor 120. This signal is transmitted to the power output circuit illustrated in figure 11. An output signal on conductor 120 will cause transistor 266 to conduct and the resulting signal conveyed along conductor 96 to valve 76 will turn off the valve. Moreover, the valve will be maintained off until the battery is replaced.
A presently available nine volt lithium battery has a capacity of 1.1 Ah which corresponds with 3,960 Asec. In the standby state, detection system 50 draws approximately 100 µA; which corresponds with 8.64 Asec. per day (100 µA X 86400 sec/day). By adding the current demands of the detection system during operation and the current drawn by the solenoid valve upon actuation, both of which are a function of the number of cycles per day, a table an be constructed to establish the useful life of the battery as a power supply. Such a table appears below
It is therefore evident one can expect at least a year of use before replacement of the battery will be necessary.
There is a growing demand by industry, governments and various commercial interests to install individual automatically operating faucets. At such locations, the space available for sensors, electronic circuitry and power supplies is at a premium. To meet his need, apparatus has been developed for mounting the control circuitry within the faucet spout itself. Such mounting eliminates constraints placed upon the wash basin and upon supporting and ancillary equipment attendant the wash basin and its mounting. Miniaturization can be achieved, as described hereinafter, with a programmed (programmable) microchip and a printed integrated circuit having surface mounted components. Within this technology, the fixed value components are generally surface mounted while the variable components or parameters are programmed in a microchip. Such miniaturization permits combining the elements or their equivalents and the functions performed by modules 30 and 36 (see figure 6) on a microchip in combination with sensor 22. Thereby, the mounting space is reduced and it becomes feasible to mount the sensor and its control circuitry within the spout of a water basin or the like.
As described above, a water flow cycle of twenty (20) seconds with a six (6) second delay between cycles provides adequate and satisfactory results. However, such predetermined time periods do not optimize water conservation. By turning the water flow on and off automatically as a function of actual use, further water conservation can be effected. To eliminate continuing water flow due to a foreign object within the detection field or to prevent cessation of water flow when a user is momentarily out of the detection field, special parameters must be accommodated.
The water flow is initiated upon sensing of a human body part within the detection field and the water flow will continue for a preset time period unless otherwise modified. Interruption of the water flow will occur if a human body part is not sensed within the detection field for a discrete period of time, such as approximately 2.5 seconds. This time period will preclude cessation of water flow during a momentary removal of the human body part from within the detection field and yet bring about a cessation of water flow when a user would normally be performing another function on completion of washing the body part. A time delay between water flow initiation periods can be preserved to reduce the likelihood of rapid on/off cycling due to abuse. Because of the programmability of the microchip, numerous other functions can be initiated and controlled as a function of the sensing of a human body part within the detection field. These functions include automatic soap dispensing, automatic actuation of air dryers, automatic dispensation of hand towels, water temperature control, light actuation, air exhaust, and various building facility control functions. As described above, the microchip can be mounted aim ,st anywhere when space is at a premium.
Referring to figure 13, there is shown a flow diagram of the functions performable by a miniaturized and programmable version of the previously described apparatus. The transmitted radiation is sensed 400 by sensor 22 provided that the human body part is within detection field 20 (see figures 3 to 5) of the sensor. The output signal from sensor 22 is transmitted through conductor to an amplifier and band pass filter.
The variant of the passive system illustrated in figure 1 3 is normally in its standby state, which requires a very, very low power demand. Hence, until sensor 22 detects 400 the presence of a human body part, minimal demands are made upon the power supply. As described previously, the variant is passive, which means that it does not generate a signal for transmission to determine the presence of an object of interest. Instead, the variant simply receives and detects receipt of radiation in a limited frequency range. Furthermore, the detection field can be limited or expanded as a function of sensor 22 and any restrictor used in conjunction therewith to limit or modify the horizontal and vertical parameters of the detection field. Such limited detection field will prevent spurious actuation which unnecessarily draws power. Moreover, with the limited detection field, the sensitivity of sensor 22 can be optimized for the environment and for utilitarian purposes.
In response to the presence of a human body part sensed 400 by sensor 22, an output signal is generated and transmitted 401 to amplifier and band pass filter. The output signal therefrom is transmitted to a microprocessor control circuit (not shown). The output signal from the amplifier and band pass filter is then transmitted 402 to a programmable positive and negative level detector within the control circuit. This detector has a variable plus and minus voltage threshold, which threshold is settable by, for example, a pair of external pins. Depending upon the setting of these pins as shown in the chart below,
the sensitivity is varied. Depending upon the degree of excursion from 2.5 volts, the standby mode will or will not be maintained.
Because different environments are contemplated with different levels necessary to generate an effective and actuating detection signal, the thresholds of sensitivity are adjustable. That detector now performs a comparison 403. If the signal detected by the detector is not higher or lower 403 N than the values set as a function of the position of pins 1 and 2, the control unit will remain in the standby state. If the signal is greater or lower 403 Y than the values set, the control unit will proceed to an active state.
To ensure availability of sufficient power to perform the functions necessary, the battery voltage is sensed, as reflected by interrogator 404. Should the voltage be less than 7.5 volts 404 Y, a first control signal is generated 405 for a time period, such as six seconds. This signal will actuate a power driver which provides power to a peripheral buzzer, which buzzer may have a frequency of for example 3 kHz. Substantially simultaneously, a timer is actuated 406 to provide a five second delay before there will be proceeded to the passive state from the active state, thus blocking the operation of the valve. If the voltage equals or is higher than 7.5 volts 404 N the active state remains.
There is then checked 407 if the battery voltage is in the range of 7.5 volts to 8 volts. A signal is generated 408 in order to power a buzzer if the voltage is in the range of 7.5 to 8 volts 407 Y. This buzzer will emit a 2 kHz tone for a period of three seconds to provide a warning to an operator. Since this voltage range is acceptable, a second control signal is generated 409 to permit resumption of the active state. On receipt of the second control signal, a pulse generator having a program enable pulse width generates 4 1 0 a further output signal to a power driver. The power driver provides electrical power to turn the valve on. Simultaneously, the power driver may be electrically connected to energize a soap dispenser. Under control of timer started 411 upon activation of the power driver, the power driver will be actuated to maintain the valve on for at least five seconds. After the five second interval 412 Y, an output signal may be generated by the timer to energize 413 a pulse generator to actuate a poker driver connected to a dryer.
Interrogator 414 receives a signal while the control unit is in the active state. The interrogator is programmable to provide a timing function of 15, 20, 25 or 30 seconds. If a signal is generated by sensor 22 on completion of the initial 5 second period, 414 Y, an output signal is generated 415. Such output signal will continue for the set period of 15-30 seconds. An interrogator 416 determines whether the control unit has been programmed to remain in the active state for a fixed period of time. If not 416 N, a signal is generated 417. That signal is provided to a programmable positive and negative level detector. External to the control unit is a signal generator which supplies a median output signal of 2.5 volts to that detector. This generator includes a pair of pins or switches settable to provide for discrete voltage ranges above and below the median voltage of 2.5 volts, as indicated in the table below.
In the event that detector senses 418 N a voltage level between one of the four set ranges of voltage for a period of one second, as determined by interrogator 418, an indication exists that a human body part is no longer within the detection field sensed by sensor 22. This results from the lack of excursion of the voltage beyond the limits of the sensitivity range set and the need for continuing water flow is not present. An output signal will then be generated 419. That signal will energize 420 a pulse generator to produce an output signal. That output signal will energize 421 a power driver and provide an output signal to turn off water valve.
In the event the detector detects 418 Y a voltage level either above or below the threshold voltages, interrogator 418 will generate an enabling signal 422 to permit the control unit to remain in the active state. Similarly, if interrogator 416 determines that the water valve has been programmed to remain on for a set period of time if such period of time has not elapsed, an enabling signal 422 will be generated to maintain the control unit in the active state. On completion of the time period set by interrogator 414 or upon other shutoff signal generated for valve, programmable hold off timer will be enabled 423. This timer provides a settable delay of 2.5 or 5 seconds 238 before the detector can be enabled to switch the control unit from the passive state to the active state.
Interrogator 414 includes a settable timed period, which period may be set by two switches on external pins in accordance with the table below

Pin 1 Pin 2

0 - 1 15 seconds

1 - 0 20 seconds

0 - 1 25 seconds

1 - 1 30 seconds

Thus interrogator 414 can be set for a maximum period of water flow. Furthermore, interrogator 414 includes a further pin which will permit disregard of voltage levels necessary for detector 419 to provide a signal to continue water flow. Thus, interrogator 414 can be set to provide a predetermined water flow time period irrespective of continuing sensing of the presence of a human body part within the detection field sensed by sensor 22.
The timer (activated upon 423) can be settable by a switch or pin to delay for a preset time period, or recovery time, return of the control unit to an active state.
The power is for example provided by a 9 volt battery. The battery supplies power to a power supply from which electrical power is distributed a plurality of conductors. A reset includes a counter which will count up to 32 seconds, at which time a pulse is transmitted to generator 421 to turn off valve. On completion of this pulse, nominally 20 milliseconds (msec), the control unit is reset and it becomes operational.
The control unit along with the ancillary equipment controlled and operated thereby has been specifically designed to minimize current demand. Based upon computation of current demand, the following table reflects the operating time available from a single 9 volt 1.1 Ah battery
As will be evident from this table, use of the present invention prior to battery change is expected to be well in excess of two years. Such effective battery life will permit use at remote locations and at locations where battery replacement is difficult or inconvenient.
Referring to figure 14, there is illustrated a three user position wash basin 270 which may incorporate the present invention to control and regulate operation of each of three water spouts 272,274 and 276 as a function of the presence of a user (body heat) in proximity to the respective user position about the wash basin. The wash basin includes a generally semicircular bowl 278 having a splash panel 280 to accommodate locating the wash basin against a wall. In a wash basin of this configuration, the three user positions are the front center, and the right and left sections rearwardly of center. Spouts 272, 274 and 276 are located within an overhanging cabinet 282, including a cover 283, in general correspondence with the user positions. A source of hot and cold water may be provided through hoses 284, 286 from respective sources to a mixing valve 288. The output of the mixing valve may be conveyed through a pipe 290 to a manifold or the like (not shown). Three conduits, 292, 294 and 296 extend from pipe 290, or an attached manifold, to interconnect spouts 272, 274, 276, respectively, with pipe 290. In conjunction with each spout, a sensor 302, 304 and 306 may be mounted in the respective one of modules 308, 310 and 312. These sensors may be of the type discussed above and identified by numeral 22. Furthermore, restrictors may be incorporated with the sensors to focus the detection field at and about each respective user position. The control and regulatory circuitry attendant each sensor may be mounted upon a microchip, as discussed above, to provide programmed and programmable functions. Each of these microchips may be mounted upon or as part of the respective one of modules 308, 310 and 312. Thus, the control of regulatory circuitry in conjunction with the respective one of the sensors may be located adjacent the respective one of spouts 272, 274 and 276.
While the principles of the invention have now been made clear in an illustrative embodiment, there will be immediately obvious to those skilled in the art many modifications of of structure, arrangement, proportions, elements, materials and components used in the practice of the invention which are particularly adapted for specific anvironments and operating requirements without departing from those principles.

Claims

1. An apparatus for controlling the operation of a fluid flow control valve in response to the presence of a living body part comprising means for operating the valve in order to control said fluid flow therethrough, said operating means comprising means for opening and means for closing said valve, characterized in that it further comprises in combination :

(a) a sensor for detecting heat radiating from a living body part within a predetermined detection field and for producing an output signal in response to such detection ;

(b) a low voltage power source for energizing said apparatus ;

(c) means for determining the voltage of said power source ;

(d) means responsive to the output signal for comparing the determined voltage with at least one predetermined voltage and for generating a first control signal if the determined voltage is below the predetermined voltage ; and

(e) means for blocking fluid flow through said valve in response to said first control signal.

2. An apparatus according to claim 1, characterized in that said opening means are provided for opening the valve in response to the output signal, said blocking means being provided for closing the valve in response to said first control signal.

3. An apparatus according to claim 1, characterized in that said comparing and generating means are further provided for generating a second control signal if the determined voltage is above the predetermined voltage, and said apparatus further comprising means for enabling said opening means in response to said second control signal.

4. An apparatus according to anyone of the claims 1 to 3, characterized in that it comprises means for amplifying the output signal.

5. An apparatus according to anyone of the claims 1 to 4, characterized in that it comprises means for preempting opening of the valve for a set time period subsequent to closing of the valve.

6. An apparatus according to anyone of the claims 1 to 5, characterized in that it comprises means for providing an alarm signal in response to said first control signal.

7. An apparatus according to anyone of the claims 1 to 6, characterized in that said sensor is a bipolar device having a first element responsive to the ambient temperature and a second element responsive to heat radiated from the body part and including means for generating the output signal in response to a change in temperature difference between the temperature sensed by the first and second elements.

8. An apparatus according to anyone of the claims 1 to 7, characterized in that it includes means for monitoring the continuing presence of heat radiating from the body part and means for actuating said closing means after a predetermined period of time of absence of heat radiating from the body part.

9. An apparatus according to anyone of the claims 1 to 8, characterized in that said determining means, said comparing and generating means and said control means are provided upon a common microchip.

10. A microchip for an apparatus according to claim 9, characterized in that it comprises said determining means, said comparing and generating means and said control means.

11. A method for controlling the operation of a fluid control valve in response to the presence of a living body part comprising opening and closing the valve, characterized in that it comprises the steps of :

(a) supplying a low voltage power for said controlling of said valve,

(b) detecting heat radiating from a living body part placed within a predetermined detection field and producing an output signal in response to said detecting;

(c) determining said supplied low voltage

(d) comparing said determined voltage with at least one predetermined voltage in response to the output signal and generating a first control signal if the determined voltage is below the predetermined voltage ; and

(e) blocking fluid flow through said valve in response to said first control signal.

12. A method according to claim 11, characterized in that said valve is opened in response to said output signal and said valve is closed in response to said first control signal.

13. A method according to claim 11, characterized in that upon said comparing a second control signal is generated if the determined voltage is above the predetermined voltage and said valve is opened in response to said second control signal.